This invention relates to position control devices for positioning speed controllable motors in general and more particularly to an improved device of this nature in which a brushless tachometer generator is utilized to furnish both velocity and position feedback information.
Position control devices for controlling speed controllable motors are known in the art. Typically, such devices include means such as a potentiometer to set in a desired position, a position controller having as inputs the desired value set on the potentiometer and an actual value from a feedback device coupled to the motor, a speed or velocity controller having as inputs the output of the position controller and velocity feedback from a tachometer generator, along with a current controller, having as an input the output of the velocity controller, which supplies the current to the motor to cause it to be driven to the proper position at a controlled velocity. In such devices, there is a need for position feedback such as from a potentiometer which is mechanically coupled to the shaft of the motor along with the tachometer generator which provides velocity feedback.